Electrical connector assembly



May 26, 1942. A. L. w. wlLLlAMs ELECTRICAL CONECTQR ASSEMBLY Drignl Filed March 20, I1939 Patented May 26, 1942 ELECTRICAL CONNECTOR ASSEMBLY Alfred L. W. Williams, Cleveland Heights, Ohio, assignor to TheBrush Development Company, Cleveland, Ohio, a corporation of Ohio Original application March 20, 1939, Serial No. 262,878. Divided and this application July 2.0, 4 1940, Serial No. 346,604. In GreatBritain March 20, 1940 7 claims. (ci. 173-328) This application is a division of application Serial No. 262,878, led March 20, 1939.

This invention relates to acoustic devices such as transmitters and receivers and to connecting means for electrical apparatus especially adapted for use on receivers of small size An object of this invention is to provide a small, thin connecting means suitable for use on a wide variety of devices but especially adaptedior use on acoustic devices of small size intended for inconspicuous wear by individuals of impaired hearing.

Another object ol this invention is to provide an improved construction for piezoelectric acoustic devices of small size.

Another object of this invention is to provide an improved means for connecting a piezoelectric unit to an acoustic diaphragm.

For the purpose of illustration the invention will now be described with reference to the accompanying drawing. In order to better illustrate some of the smaller parts, all of the ilgures are larger than the actual devices are apt to be made, but the invention should not be limited to any particular dimensions. Figures 6 to 11 inclusive are drawn on a largerl scale than the remaining figures.

Fig. 1 is an edge elevation of an acoustic device embodying the features of this invention.

Fig. 2 is a plan view of the device of Fig. 1.

Fig. 3 is a view similar to Fig. 2 but with the connector removed to reveal the terminals of the acoustic device.

Fig. 4 is a plan view of the connector.

Fig. 5 is an edge elevation of the connector of Fig. 4.

Fig. 6 is a plan view of the acoustic device lof Figs. 1 to 3, showing the opposite side, with some of the parts broken away to reveal inner construction.

Fig. 7 is a sectional view on the line 1, 1 of Fig. 6.

Fig. 8 isa sectional view on the line 8, 8 of Fig. 6.

Fig. 9 is a sectional view of an alternative diaphragm construction.

Fig. 10 is a plan view of the terminal side of the connector shown in Figs, 4, 5, '1 and 8, with some of the parts broken away to reveal inner construction.

Fig. 11 is a sectional view on the line Il, II of Fig. 10.

Fig. 12 is a plan view of a separate receptacle for the connector of Figs. 4, 5, 10 and 11.

Fig.l 13 is a side elevation of the receptacle,

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Fig. L14 is an edge elevation of the receptacle. Fig. 15 is a sectional view taken on the line I5, I5 of Fig. 12 with a contact member vshown Y in elevation.

Fig. 16 is a sectional view showing a receptacle in cross-section corresponding to that of line I6, I6 of Fig. 15, said receptacle being secured to a portion of a wall section of electrical apparatus.

In Figs. 1 to 11, the acoustic device comprises a cup-shaped housing I of hard rubber, Bakelite or any other suitable insulating material having a main wall section la and circular wall section Ib. Within the housing is disposed a substantially rectangular piezoelectric bimorph unit 2 of the`bending type such as is disclosed in United States Letters Patent Reissue 20,213. The unit is supported at its ends on small blocks 3, 3 of soit material such as viscoloid or rubber. which are supported by the wall section la of the housing. The blocks 3, 3 may readily be secured to the unit and housing by cement. The ends of the unit are slightly beveled to permit use of a larger unit than would otherwise be possible.

The outer face of main wall section la carries a, connector receptacle comprising connector retaining flanges Ic, Ic which may, as shown, be formed as integral parts of the housing I. The receptacle further comprises thin strip-like terminal contacts 4, 5. The terminals l and 5 are mounted in channel-shaped recesses in the outer face of wall section Ia by forcing the terminal ends through suitable engaging recesses in the wall section. The end la of terminal It extends inwardly and terminates close to an edge of imit 2 while the other end 4b terminates ush with the inner surface of wall section la. Similarly, end 5a of terminal 5 extends inwardly and terminates close to the opposite edge of the unit 2, and the other end 5b terminates ush with the inner surface of wall section la. It is not necessary that the ends Ib, 5b extend into the wall section but such construction adds to the ruggedness of the assembly. For further strength, these ends may be made longer and bent over on the inner face of wall section Ia. The electrical leads 2a, 2b of the unit 2 are connected to ends la, 5a respectively of the terminals.

In assembling such units of very small size, it is diicult to solder the connection without damaging the "crystal unit by excessive heat. It has been found that the connections to piezoelectric units, such as unit 2, need not have the low resistance usually required in other devices as long as the connections are mechanically rigid.

A satisfactory connection may be made by wrapping the lead 2a several times around terminal end 5a and then applying a drop of cement or lacquer or other suitable binder. The binder may, if desired, contain particles of a conducting material.

Onthe outer face of unit 2, approximately midway between its ends, is cemented a ring 6 of yielding vibration conductive material such as viscoloid or rubber. A diaphragm 1 of suitable material such as Celluloid, aluminum, Bakelite or mica is secured to the wall section Ib oi? the casing by cement or other suitable means and at its inner face is cemented to the ring 6.

When a circuit supplying a voltage of sound frequency is connected to the terminals 4, 5i the through ring 6to the unit 2, and as a result, an

alternating voltage appears between terminals d and 5.

It has been found that when a ring-like member such as AIi in Figs. 6, 7 and 8 is substituted for other coupling means between a piezoelectric unit and a diaphragm,'the ratio of acoustic output to applied voltage is increased and, conselquently, a device using this new coupling means may be reduced in size. 'I'he increase in sensitiv` ity probably results from the better distribution of forces over the diaphragm so that the net volume displaced by the diaphragm is greater, and from the more favorable mechanical impedance match between the piezoelectric unit and x the diaphragm. Due to the thinness of the ring,

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and suitably engaging threads on the outer surface of wall section I a.

To connect an external electrical circuit to the terminals Il, 5 a connector -9 is provided. It comprises a main body member I 0 molded of suitable insulating material and having a flat face Illa. Outwardly projecting flanges Illb, Ib are adapted to engage connector retaining ilanges Ic, Ic of the connector receptacle which are :arried by the mainl wall section Ia of the acoustic device. Projections I 0c, IDc at one end of' the connector serve as stops which engage ends of retainer flanges Ic to locate the connector on the device. The connector is proy vided with two main recesses II, II separated by a thin wall I2. Within each recess is disposed a generally U shaped spring strip contactor member, designated as I3 and I4, formed of thin spring brass or other suitable material. When the connector 9 engages the receptacle, the contactor members I3 and I4 register with terminals 4 and 5 and are slightly compressed so as to be held against said terminals under slight pres- Two slots I5, I5 formed in the connector body I extend from one end face into the recesses'II and outwardly toward the ilat face Illa. Flexible lead wires I6, I6 iit into the slots with a tight press fit an-d are further held by a suitable cement I5a (Figs. 7 and 11) The wires are soldered` to the inner .ends I3a, .Illa of the contactor members. In Fig. 10 part of contactor member I3 is broken away to reveal the soldered joint. The outer ends I3b, I 4b of the contactor members iit into shallow extensions II a, II a of recesses I I, II. A thin plate I1 of suitable insulating material is cemented into a registering cavity I1a to form an overhanging portion of the body which loosely holds the ends I3b, Idb of being a large area of contact with the diaphragm.

Furthermore, the ring need not be a separate member cemented to the diaphragm, It may be formed as a part of the diaphragm, for example, as shown in the sectional view, lFig. 9. In 'this figure the diaphragm 1a is molded or otherwise formed with a ring 6a projecting from one side. The diaphragm 1a with its integral ring 6a may be substituted for diaphragm 1 and 'cemented ring 6 in the device of Figs. 1 to 6.

When used as an earphone, the device of Figs. 1 to 11 may be held close to the users ear in any suitable manner. One convenient arrangement for an earphone of small size is to Aprovide the phone withla metal shell 8 (shown in Fig. l, and represented indotted outline in Fig. 7) having a projection 8a which is adapted to engage a recess 'in an ear insert memberor earpiece of the type commonly used with Hearing aid devices. The shell 8 may be secured to the to or by providing a threaded recess in the insert` the contactor members in alignment in their recesses. In Fig. 10 the plate I1 is partly broken away to better reveal the inner construction.

It will be noted that an acoustic device embodying the features of this invention may be made very small and compact so as to be very inconspicuous when worn as an earphone. Several features contribute to this compactness. They include (a) the use of a thin piezoelectric actuating unit disposed in a shallow housing atwise adjacent the main wall section, (b) the use of a thin ring of yielding vibration conductive material to couple the actuating unit to the diaphragm, (c)- the use of a receptacle carried by the main wall section of the ydevice and adapted to receive in sliding engagement a thin connector and (d) location of the ends of the receptacle terminals adjacent the edges of the piezoelectric unit in a space otherwise unoccupied and in positions adapted for ready connection to the leads ofthe unit.

The relatively long U shaped construction of the contactor members in the connector insures suiiicient pressure to obtain good electrical connections and to hold the connector in place in the receptacle without requiring vgreat accuracy in the fabrication of the parts. I6, I6 are bothfpressed and cemented into the slots I5, I5 most of the stress on the wires is taken by the main body I0 rather than by the contactor members I3, I4.

It is usually unnecessary to provide polarized terminals for piezoelectric devices but it will be observed that the connector provided by this invention may engage-the receptacle from either side thus facilitating reversal of polarity and rapid and easy connection. However, if desired.,

Since the wires provided with a barrier to prevent entrance of the connector from one side.

Although in many cases it is advantageous, in the interest of compactness and simplicity, to embody the connector retaining flanges as integral parts of the electrical apparatus and to carry the receptacle terminals in a wall section of the apparatus, as illustrated in the acoustic device of Figs. 1 to 11, it may be desirable in other cases to provide as a separate unit a connector receptacle which may be secured to electrical apparatus by screws or rivets. Figs. 12 to 16 illustrate such a separate receptacle. It comprises an insulating base I8,v having connector retaining flanges la, IBa adapted to engage the iianges Ib of the connector. Generally, U shaped contact members i9 and 20 formed of thin sheet metal are carried by the insulating base and may conveniently be secured thereto by forcing their l ends through suitable apertures in the base. If desired, the ends may be twisted as shown in Figs. 13 to 16. Holes 2|, 2 I' are provided to accommodate screws or rivets for securing the receptacle to the electrical apparatus with which it is to be associated. When connector 9 is inserted in the receptacle, the contact members I9 and 20 engage contacter members I3 and I4 of the connector and sufficient pressure is maintained by members I3 and I4 to maintain good contacty and to insure that the connector remains in position. `To facilitate mounting of the receptacle, the contact surfaces of members I9 and 20 are made somewhat shorter than the corresponding contact surfaces of members 4 and 5 of the acoustic device so that the projecting ends are grouped within a relatively small space. To mount the receptacle on any device it is only necessary to provide three holes in the device, two of the holes registering with holes 2|, 2l to accommodate mounting rivets or screws and the third hole providing clearance for the ends of contact members I9 and 20. In Fig. 16 the receptacle is shown riveted toa portion of a thin sheet-like member such as the housing of an amplifier used in a portable hearing aid. Eyelets 2 2, 22 secure the receptacle to the wall 23 and the extended ends of contacts I9 and project through an opening 23a to a position permitting ready connection to the electrical circuit.

What I claim is:

1. A connector comprising a relatively thin body member of generally rectangular shape bounded partially by a flat face of greater length `than width, and by an end face, said body member having recesses therein extending inwardly from said flat face, said recesses comprising a first pair of parallel elongated grooves of generally rectangular cross-section and of greater length and depth than width extending lengthwise of said face and spaced from each other and from the bounding edges of said faces, a second pair of parallel elongated grooves of smaller cross-section extending between the ends of said rst pair of grooves and the said end face of said body, a relatively shallow transverse recess of greater length 'and width than depth disposed with its length crosswise of said second grooves, a bent spring-strip contact of generally U shape disposed in each of said first pair of grooves with one leg of said U resting upon the base of said groove and the other leg protruding beyond the surface of said flat face along a portion of the length of said groove, the end portion of said protruding leg being offset inwardly and extending beyond the nearest edge of said transverse recess, a lead-wire .disposed in each of said second grooves and in electrical engagement with a leg of the contact, a relatively thin plate disposed in said transverse recess with the lower face thereof A in engagement withl the said oiset end portions of said contacts. i

2. An assembly particularly adapted for interconnecting electrical circuits, said assembly comprising the combination of a base section having a plate-like lwall of insulating material; a slider section of insulating material adapted for sliding movement on a face thereof While said face is in flatwise relationship to a face of the wall of said base section; interlocking means on said base and on said slider section adapted for mutual interlocking relationship to constrain the slider against motion out of said face to face relationship with said wall lwhile permitting the slider to be connected to and disconnected from the base by sliding it rectilinearly over the said wall; contacts disposed on said wall in symmetricall relation to said interlocking means; contactors on said slider section for engagement with the contacts of said wall when the two sections are interlocked in mutual sliding engagement in said face to face relationship; conductors secured in electrical engagement with said contactors and passing outwardly from said slider in a direction paralleling the sliding direction of the latter; stop means on said slider section for limiting the motion of the latter in the direction of strain on said conductors.

3. An assembly particularly adapted for interconnecting electrical circuits, said assembly comprising the combination of: a plate-like base section of insulating material having atleast a pair of elongated strip-like contacts disposed on an outer face thereof in substantial parallelism and in spaced-apart relationship; a slidable plate-like removable section having a ilat face adapted for sliding movement over the outer face of said base; means on said base and on said slidable section adapted for mutual interlocking engagement to constrain the slider against motion out `of its face to face relation to said outer face of the base, while permitting the slider to be connected to and disconnected from the base by sliding it in directions paralleling the longitudinal axes of said contacts, said means being disposed symmetrically with respect to said contacts; contactors on said removable section for engagement with the contacts of said base when the two sections are mutually interlocked in sliding engagement; conductors secured in electrical engagement with said contactors and passing outwardly from said slidablesection in a direction paralleling the sliding direction of the latter; stop means on said slidable section for limiting the motion of the latter in the direction of strain on said conductors.

4. An assembly particularly adapted for interconnecting electrical circuits, said assembly comprising the combination of: a plate-like base section having an open-ended channel-shaped chamber whose base is of insulating material and is substantially flush with an outer face of said plate-like base; a pair of contacts in said chamber disposed symmetrically on opposite sides of the longitudinal center line of said chamber; a slidable plate-like removable section having a substantially rectangular face, and adapted for sliding movement into said chamber from either end of the latter in a direction parallel to an edge of said face while the latter is in face to face relation to the base of said chamber; contactors on the removable section to engage with the contacts of the base section when the removable section is slidably positioned in said chamber; conductors secured to said contactors land passing outwardly from said slidable section in a direction parallel with the sliding direction of the latter; means in said chamber and on said slidable section adapted for mutual interlocking engagement to constrain the slider against motion out of its face to face relationship with the base of said chamber while permitting the slidable section to be connected to the base section by rectilinear sliding motion in the direc-g tion of strain on said conductors, and to be disconnected therefrom by rectilinear sliding motion opposite to the direction of strain on said la plate-like wall of insulating material; a pair of elongated strip-'like contacts disposed a'twise on an outer face of said wall in substantial parallelism and in spaced-apart relationship,`op posite ends of said contacts extending through said Wall to the inner face thereof; a pair of elongated upstanding guides disposed on said outer face-on opposite sides of said contacts and in symmetrical relationship thereto, to dene with said wall an open-ended channel-shaped chamber, the base of which is ush With said outer face; a plate-like slider section adapted to slide into said chamber from either end thereof while having one of its faces disposed in face to face relationship with the base of said chamber; a pair of reslliently mounted contactors embedded in said slider for engagement with said contacts when said slider is assembled with said base section in the said face to face relationship with the base` of said chamber; a pair of conductors secured in electrical engagement with said contactors and passing outwardly from said slider in a direction paralleling the sliding direction of the latter; interlocking iianges on said guides and on opposite sides of said slider direction of strain; and lateral stop means on said slider adapted for engagement with an end of a guide to limit the motion of the slider in the said direction of strain and to position said slider in said chamber with its contactors in electrical engagement with said contacts."

6. A connector adapted for connection with a receptacle by rectilinear sliding motion and comprising: a relatively thin body member bounded partially by a flat face and contiguous side faces, said body having a pair of elongated recesses extending inwardly from saidA flat face and thence extending longitudinally under an oveshanging portion of said fiat face; a Apair of bent spring-strip contacts disposed one in each of said recesses and adapted to be joined electrically to lead-wires which enter said body through one of said side faces and extend longitudinally into said recesses, each of said contacts having an intermediate portion thereof resiliently mounted to project outwardly beyond the surface of said at face and having an end portion adjacent said intermediate portion disposedY under the overhanging portion of said flat face to limit the pro- `jection of said resilient intermediate portion; and a pair of flanges adapted to interlock with complementary flanges on said receptacle, said flanges being disposed in substantial parallelism -on opposite sides of said flat face so as to be in symmetrical `relation to said pair of recesses.

7. A connector adapted for connection with a receptacle by rectilinear sliding motion, said connector comprising: a body member bounded by a flat face'and an adjoining end face, said body member having a pair of elongated recesses extending inwardly from said flat face and thence extending longitudinally under an overhanging portion of said at face, said recesses being of generally rectangular cross-section; a pair of bent spring-strip contacts of generally U shape disposed one in each of said recesses with one leg of said "U above the other, with a surface portion of said upper leg projecting outwardly beyond the surface of said at face, and with the end portion of said leg restrained under said overhanging portion; a pair of conductors disposed longitudinally in said recesses t in electrical engagement with said lower legs and for constraining the slider against motion out'4 of said face to face relationship with the base of said chamber while permitting the slider to be connected to the base section by rectilinear sliding motion in the direction of strain on said conductors, and to be disconnected therefrom by rectilinear sliding motion opposite to the said extending out of said body through` an end face thereof; and a pair of anges adapted to interlock with complementary flanges on said recep tacle, said anges being disposed substantially inuparallelism onl opposite sides of said at face y and of said recesses so as to be in symmetrical 

